I watched the video earlier today, and well, the Brawl competitive comments made by Omni weren't just questionable, but outright inaccurate going off memory here. It just...made no sense. I can see why Omni would give it top marks for single player content aside from the battles themselves, but there's a reason why Brawl is considered so bad, and this is coming from someone who started their local competitive play in Brawl (but now play PM almost exclusively). It's riddled with horrendous design decisions. Even the recent video with M2K and ZeRo, where they talk about transitioning from Melee to Ultimate, had M2K basically say the game punished him by landing an aerial, and he got punished with an aerial back. Hitstun can be cancelled on frame 13 with an aerial or air dodge. That alone prevents so many things like kill confirms or juggles that aren't true combos/chaingrabs. Tripping and movement being reduced significantly hurt it as well. Plus with how many characters were nerfed drastically, and how dominant multiple newcomers were, the overall cast viability was complete trash before the meta completely stagnated. I had heard Fox getting some results before the meta died, but otherwise, that's all I know about potential character performance.
Also I can see why he would give Smash 4 competitive a somewhat similar score. The game is largely just a more polished Brawl, but while it dials back defensive options somewhat, it makes recovering so easy. Also the game still doesn't have a good juggle system overall. Air dodge duration was decreased, thereby making them faster and safer overall in the air. Plus hitstun could be cancelled on frame 40 with an air dodge, and frame 45 with an aerial, so follow ups were still quite limited in a game with a slow engine that doesn't conserve momentum, most things are slow, and overall moves with high knockback. Which is why you see generally grab throws into a uair then reset to neutral, or just one or two hits in general before a reset to neutral in Smash 4. It is an improvement overall than Brawl, and doesn't make the same level of mistakes, but it's not that much of an improvement to change the underlying issues Brawl had: defensive, slow, does not reward aggression. Also with Bayonetta existing in Smash 4, it began to suffer the exact same problem Brawl had with Meta Knight. One character is so dominant in the meta that any character's MU versus them would very much determine tier placing, and in turn starts to stagnate the meta even more.